/Engine/Source/Editor/UnrealEd/Public/EditorViewportLayoutThreePanes.h
class FEditorViewportLayoutThreePanes : public [FAssetEditorViewportPaneLayout](API\Editor\UnrealEd\FAssetEditorViewportPaneLayout)
FName
PerspectiveViewportConfigKey
TSharedPtr<SSp...
PrimarySplitterWidget
The splitter widgets
TSharedPtr<SSp...
SecondarySplitterWidget